Robotic vacuum cleaners are know in the art, which are equipped with drive means in the form of a motor for moving the cleaner across a surface to be cleaned. The robotic vacuum cleaners are further equipped with intelligence in the form of microprocessor(s) and navigation means for causing an autonomous behaviour such that the robotic vacuum cleaners freely can move around and clean a space in the form of e.g. a room.
Traditionally, robotic vacuum cleaners have been arranged with circular-shaped main bodies. Such a robot having co-axial drive wheels at the centre of its body has the advantage that it is easy to control and cannot get stuck since it always can rotate 180° and go back the same way it came. However, the circular-shaped main body makes them unsuitable for cleaning corners or edges where a floor meets a wall since these circular vacuum cleaners due to their shape cannot move into a corner or close enough to a wall. An example of a robotic vacuum cleaner aiming at solving this problem is disclosed in WO 03/024292, the main body of which at its rear end is circular-shaped, whereas the front end of the main body is substantially rectangular. Further, sweeping brushes are arranged at a bottom side of the main body and disposed such that they are associated with front corner regions of the rectangular-shaped main body front end. This is an improvement over the traditional circular-shaped robotic vacuum cleaners in terms of reaching into corners. However, the shape of the robotic vacuum cleaner disclosed in WO 03/024292 is still not optimal for navigating corners, for turning around in a narrow space such as a corridor, or for navigating in between furniture, since its main body rear end will bump into the wall leading into the corner once the vacuum cleaner turns the corner into which it has moved, for pursuing the wall leading out of the corner.